Factor Analysis of Unintended Initial Dissection of the Posterior Plane

Identification of Factors Related to Unintended Initial Dissection of the Posterior Plane in Small Incision Lenticule Extraction Cases by Three Different Surgeons

To explore the potential factors for unintended initial dissection of the posterior plane in a large sample retrospective analysis and surgeons of different levels.

Study Overview

• Status: Completed
• Conditions: Myopia; Small-incision Lenticule Extraction (SMILE) Surgery
• Intervention / Treatment: Procedure: Small incision lenticule extraction

Detailed Description

Myopia is the most common eye disease in the world. Femtosecond laser small incision lens extraction (SMILE) has increasingly become the first choice in refractive surgery due to its greater biomechanical stability, less impact on the tear film and other advantages. However, because SMILE surgery is more challenging than flap-based corneal ablative surgery, young surgeons sometimes dissect the lenticule posterior plane first in clinical practice, which will make it more difficult to extract the lenticule or even cause the retained lenticule. The purpose of this study aims to explore the potential risk factors for unintended initial dissection of the posterior plane in large samples and surgeons of different surgical volumes and different surgical habits (different angles of peripheral corneal incision) in multiple scenarios.

• Study Type: Observational
• Enrollment (Actual): 3003

Contacts and Locations

Study Locations

• China
  • Jiangxi
    • Nanchang, Jiangxi, China, 330000
      • The Second Affiliated Hospital of Nanchang University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients from clinics in ophthalmic center of the second Affiliated Hospital of Nanchang University

Description

Inclusion Criteria:

• A condition in which the spherical equivalent refractive error of an eye is ≤ -0.50 D when ocular accommodation is relaxed;
• Age ≥18 years;
• Spherical equivalent (SE) ≥ -10.0D;
• Corrected distance visual acuity (CDVA) ≥ 16/20;
• Stable myopia for at least 2 years;
• No contact lenses wearing for at least 2 weeks.

Exclusion Criteria:

• The presence or history of eye conditions other than myopia and astigmatism, such as keratoconus or external eye injury;
• A history of eye surgery;
• The presence or history of systemic diseases.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Eyes with SMILE surgeries; Eyes with SMILE surgeries which were performed by three surgeons with different experiences.

Procedure: Small incision lenticule extraction; Small incision lenticule extraction surgeries performed by two Refractive surgery experts (Refractive surgery expert 1: YYF, Associate Professor with 10 years of experience as a refractive surgeon; Refractive surgery expert 2: GF, Associate Professor with 5 years of experience as a refractive surgeon) and a Attending ophthalmologist (WNY, Attending ophthalmologist with 1 year of experience as a refractive surgeon).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The number of patients with unintended initial dissection of the posterior plane in the SMILE surgeries	The number of patients with unintended initial dissection of the posterior plane were observed during the SMILE surgeries.	Day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The impact of spherical equivalent on the unintended initial dissection of the posterior plane (UIDPP) in SMILE surgeries	The spherical equivalent of eyes with UIDPP and eyes without UIDPP were analyzed, and statistical analysis was observed to investigate the impact of spherical equivalent on the UIDPP in SMILE surgeries.	Day 0
The impact of peripheral corneal incision angle on the unintended initial dissection of the posterior plane (UIDPP) in SMILE surgeries	The peripheral corneal incision angle of eyes with UIDPP and eyes without UIDPP were analyzed, and statistical analysis was observed to investigate the impact of peripheral corneal incision angle on the UIDPP in SMILE surgeries.	Day 0
The impact of peripheral lens thickness on the unintended initial dissection	The peripheral lens thickness of eyes with UIDPP and eyes without UIDPP were analyzed, and statistical analysis was observed to investigate the impact of peripheral corneal incision angle on the UIDPP in SMILE surgeries.	Day 0
The impact of lens diameter on the unintended initial dissection	The lens diameter of eyes with UIDPP and eyes without UIDPP were analyzed, and statistical analysis was observed to investigate the impact of lens diameter on the UIDPP in SMILE surgeries.	Day 0
The impact of central corneal thickness on the unintended initial dissection	The central corneal thickness of eyes with UIDPP and eyes without UIDPP were analyzed, and statistical analysis was observed to investigate the impact of central corneal thickness on the UIDPP in SMILE surgeries.	Day 0

Collaborators and Investigators

• Sponsor: Yifeng Yu

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2021
• Primary Completion (Actual): September 1, 2021
• Study Completion (Actual): September 1, 2021

Study Registration Dates

• First Submitted: April 29, 2022
• First Submitted That Met QC Criteria: May 7, 2022
• First Posted (Actual): May 10, 2022

Study Record Updates

• Last Update Posted (Actual): May 10, 2022
• Last Update Submitted That Met QC Criteria: May 7, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Keywords: femtosecond laser; small-incision lenticule extraction (SMILE); unintended initial dissection of the posterior plane
• Additional Relevant MeSH Terms: Wounds and Injuries; Surgical Wound
• Other Study ID Numbers: [2021] No. (031)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No